1. Field of the Invention
The present invention relates to a cleaning device for semiconductor inspection devices and particularly to an abrasive member and a cleaning device for a probe needle for a probe card.
2. Description of the Background Art
Conventionally, a device referred to as a probe card has been used in the inspection process of semiconductor devices. FIG. 15 is a cross section of a conventional probe card. The conventional probe card shown in FIG. 15 has an opening 114 formed approximately at the center of a substrate 116. Provided around opening 114 are a plurality of probe needles 111 towards the center of opening 114. Probe needle 111 is connected via a wiring to a terminal (not shown) arranged at a periphery of substrate 116. In inspecting a semiconductor device, the terminal is connected to an inspection device referred to as a prober. The probe card is arranged opposite to a surface of a semiconductor device to be inspected and is also arranged to allow the tip of probe needle 111 to come in contact with an electrode formed on the surface of the semiconductor device. Electrical characteristics of the semiconductor device are thus inspected via probe needle 111 in contact with the electrode formed on the surface of the semiconductor device.
FIG. 16 is a schematic diagram for illustrating the conventional probe needle 111 shown in FIG. 15. In FIG. 16, a lead portion of the probe needle has a diameter D of approximately 0.25 mm, an end of the probe needle has a length L of approximately 7 mm, and a tip 112 of the probe needle that comes in contact with an electrode of a semiconductor device has a diameter d of approximately 30 .mu.m. The materials for the probe needle include tungsten or the like.
In inspecting a semiconductor device, tip 112 of the probe needle comes into contact with an electrode 105 formed on a surface of the semiconductor device, as shown in FIGS. 17 and 18. FIGS. 17 and 18 are schematic views for illustrating how the tip of the probe needle comes in contact with the electrode formed on the surface of the semiconductor device. As shown in FIG. 17, as a semiconductor device 117 is raised towards probe needle 111, electrode 105 formed on the surface of semiconductor device 117 comes into contact with tip 112 of probe needle 111. Electrode 105 of semiconductor device 117 is formed of aluminum, and a thin aluminum oxide layer 118 is formed on a surface of electrode 105. Since aluminum oxide layer 118 is an insulator, tip 112 of probe needle 111 simply pressed against electrode 105, as shown in FIG. 17, does not result in an aluminum layer 119, which is positioned under aluminum oxide layer 118, coming into contact with tip 112 of probe needle 115 and probe needle 111 cannot pass current to electrode 105.
Accordingly, semiconductor device 117 is typically further raised after tip 112 of probe needle 111 is brought into contact with electrode 105, as shown in FIG. 18. Probe needle 111 is thus elastically deformed and tip 112 of probe needle 111 is horizontally moved on electrode 105. Aluminum oxide layer 118 on the surface of electrode 105 is thus partially removed from the surface of the electrode to allow aluminum layer 119 as the exact electrode to come into direct contact with tip 112 of probe needle 111. The process shown in FIG. 18 will be referred to as an overdrive process hereinafter. Tip 112 of probe needle 111 has thus come into contact with electrode 105 in conventional inspection processes.
However, a portion of aluminum oxide layer 118 removed from the surface of electrode 105 in the overdrive process shown in FIG. 18 adheres to tip 112 of probe needle 111, as shown in FIG. 19. When a foreign matter 113, such as aluminum oxide, as an insulator thus adheres to tip 112 of probe needle 111, foreign matter 113 prevents the electrical connection between tip 112 of probe needle 111 and electrode 105 (shown in FIG. 18) of the semiconductor device, which makes it difficult to pass a predetermined current to electrode 105. Accordingly, repeated use of such a probe needle has disadvantageously resulted in an inaccurate inspection of semiconductor devices.
Accordingly, a cleaning operation of probe needles has been conventionally provided so that foreign matter 113, such as aluminum oxide, is removed from tip 112 of probe needle 111.
FIG. 20 shows a cross section of an abrasive sheet for probe needles that is used in a conventional cleaning operation of probe needles. The conventional abrasive sheet 102 for probe needles in FIG. 20 employs silicon rubber 120 as a matrix, and abrasive grains 121, such as artificial powdery diamond, are dispersedly arranged in silicon rubber 120. When tip 112 (shown in FIG. 19) of probe needle 111 (shown in FIG. 19) is stuck into abrasive sheet 102 predetermined times, abrasive grains 121 in abrasive sheet 102 allows foreign matter 113 (shown in FIG. 19) to be scratched off the surface of probe needle 111. Thus, foreign matter 113 has been conventionally removed from tip 112 of probe needle 111.
FIG. 21 is a flow chart of a conventional, probe needle cleaning operation comprising by four steps. Step 1 is the step of arranging a probe card opposite to an abrasive sheet. Step 2 is the step of sticking the tip of a probe needle into the abrasive sheet predetermined times. FIG. 22 schematically shows the tip of probe needle being stuck into the abrasive sheet the predetermined times in step 2. As shown in FIG. 22, tip 112 of probe needle 111 is stuck into abrasive sheet 102 and foreign matter 103, such as aluminum oxide, adhering to tip 112 of probe needle 111 can thus be scratched off by abrasive grains 121 in abrasive sheet 102.
When step 2 is completed, however, a viscous silicon rubber film 124 resulting from the silicon rubber as the matrix of abrasive sheet 102 (shown in FIG. 22) that is softened adheres to tip 112 of probe needle 111, as shown in FIG. 23. A foreign matter 122 also adheres to silicon rubber film 124. Foreign matter 122 includes foreign matter 113 (shown in FIG. 22), such as aluminum oxide, removed from tip 112 of probe needle 111 in step 2, abrasive grains 121 (shown in FIG. 22) removed from abrasive sheet 102, a removed portion of silicon rubber 120 as the matrix of abrasive sheet 102 and the like.
Accordingly, the conventional probe needle cleaning operation requires the step of spraying an organic solvent on the tip of the probe needle and thus removing foreign matter 122 (shown in FIG. 23) adhering to the tip, as indicated in FIG. 21. FIG. 24 schematically shows a performance of step 3. As shown in FIG. 24, an organic solvent 123 is sprayed on tip 112 of probe needle 111, silicon rubber film 124 is dissolved and silicon rubber film 124 and foreign matter 122 are thus removed from tip 112.
When step 3 is completed, organic solvent 123 adheres to probe needle 111, as shown in FIG. 25. Accordingly, the conventional probe needle cleaning operation provides the step of blowing air against probe needle 111 (shown in FIG. 25) as step 4, as shown in FIG. 21, to dry organic solvent 123 (shown in FIG. 25) adhering to the tip of probe needle 111, and simultaneously blowing off foreign matters and the like remaining on the surface of probe needle 111.
Conventional probe needle cleaning operations have thus been performed.
As described above, a conventional probe needle cleaning operation provides sticking tip 112 of a probe needle into abrasive sheet 102 predetermined times, as shown in FIG. 22, to remove foreign matter 113, such as aluminum oxide, adhering to tip 112 of the probe needle, while silicon rubber 120 as the matrix of abrasive sheet 102 is softened and becomes viscous silicon rubber film 124 which in turn adheres to tip 112 of the probe needle, as shown in FIG. 23. Accordingly, foreign matter 122 has also adhered to silicon rubber film 124 at completion of the step of sticking tip 112 of the probe needle into abrasive sheet 102 (shown in FIG. 22) the predetermined times. Thus, the cleaning step by means of organic solvent is required, as shown in FIG. 24, which increases the number of steps of the probe needle cleaning operation.
Furthermore, since the cleaning operation by means of organic solvent is provided by spraying organic solvent 123 on tip 112 of the probe needle, as shown in FIG. 24, the operator can inhale the sprayed organic solvent and thus the cleaning step can adversely affect human body and result in an unsatisfactory working environment.